The cinereous vulture (Aegypius monachus), also known as the black vulture, Eurasian black vulture, and monk vulture, is a very large raptor in the family Accipitridae distributed through much of temperate Eurasia. With a body length of , across the wings and a maximum weight of , it is the largest Old World vulture and largest member of the family Accipitridae.
Aegypius monachus is one of the largest birds of prey and it plays an important role in its various ecosystems by eating carcasses, which in turn reduces the spread of diseases. The vultures are constantly exposed to many pathogens because of their eating carrion. A study of the gastric and immune defense systems conducted in 2015 sequenced the bird's entire genome. The study compared cinereous vultures to bald eagles, finding positively selected genetic variations associated with respiration and the ability of the vulture's immune defense responses and gastric acid secretion to digest carcasses.
Taxonomy The genus name Aegypius is a Greek word () for 'vulture', or a bird not unlike one; Aelian describes the aegypius as "halfway between a vulture (gyps) and an eagle". Some authorities think this a good description of a lammergeier; others do not. Aegypius is the eponym of the species, whatever it was in ancient Greek. The English name 'black vulture' refers to the plumage colour, while the specific name monachus (monk) and 'monk vulture', a direct translation of its German name Mönchsgeier, refers to the bald head and ruff of neck feathers like a monk's cowl. The name 'cinereous vulture' (Latin , ash-coloured; pale, whitish grey), was a deliberate attempt to rename it in order to distinguish it from the American black vulture, but has also been used historically by Francis Willughby for the pale grey juvenile of the largely white Egyptian vulture.
It is most closely related to the lappet-faced vulture, with this pair then to the white-headed vulture and the red-headed vulture; all three have sometimes been included with it in a broader interpretation of the genus Aegypius.
This bird is an Old World vulture, and as such is only distantly related to the New World vultures, which are in a separate family, Cathartidae, of the same order. It is therefore not closely related to the much smaller American black vulture (Coragyps atratus) despite the similar name and colour.
Description
The cinereous vulture measures in total length with a wingspan. Males can weigh from , whereas females can weigh from . It is the largest accipitrid and is thus one of the world's heaviest flying birds.Glutz von Blotzheim, U. N., Bauer, K. M., & Bezzel, E. (1980). Handbuch der vögel mitteleuropas. Aula, Wiesbaden.Chandler, K. P. (2013). The distribution and status of cinereous vulture (Aegypius monachus) at Jorbeer, Bikaner, Rajasthan, India: A study of near threatened monk vulture. Research Journal of Animal, Veterinary and Fishery Sciences, 1(1), 17-21. Average weights were long not known to have been published for this species but the median weight figures from two sources were and .Del Moral, J. C., de la Puente, J. (2014). Buitre negro – Aegypius monachus. En: Enciclopedia Virtual de los Vertebrados Españoles. Salvador, A., Morales, M. B. (Eds.). Museo Nacional de Ciencias Naturales, Madrid. However in a Korean study, a large survey of wild cinereous vultures was found to have weighed an average of with a mean total length of , this standing as the only attempt to attain the average sizes of free-flying mature birds of the species, as opposed to nestlings or captive specimens.Kim, J. T., Park, C. M., Kim, Y. J., & Pak, I. C. (2007). Survey on the actual injured condition and wintery ecology of Black vulture (Aegypius monachus). Korean Journal of Veterinary Service, 30(3), 467-472. Unlike most accipitrids, males can broadly overlap in size with the females, although not uncommonly the females may be slightly heavier. These are one of the two largest extant Old World vultures and accipitrids, with similar total length and perhaps wingspans recorded in the Himalayan vulture (Gyps himalayensis), as indicated by broadly similar wing and tail proportions, but the cinereous appears to be slightly heavier as well as slightly larger in tarsus and bill length.Mohapatra, R. K., Sahu, S. K., Panda, S., Das, J. K., & Upadhyay, H. S. (2019). Himalayan Griffon: rescue and treatment of Gyps himalayensis in Odisha, India. ZOO'S PRINT, 34(3), 24-27. Superficially similar but only distantly related New World condors can either be of similar wing area and bulk or slightly larger in these aspects. Despite limited genetic variation in the species, body size increases from west to east based on standard measurements, with the birds from southwest Europe (Spain and south France) averaging about 10% smaller than the vultures from central Asia (Manchuria, Mongolia and northern China). Among standard measurements, the wing chord is , the tail is and the tarsus is .
The cinereous vulture is distinctly dark, with the whole body being dark blackish-brown excepting the pale head in adults, which is covered in fine blackish down. This down is absent in the closely related lappet-faced vulture (Torgos tracheliotos). The skin of the head and neck is bluish-grey and a paler whitish colour above the eye. The adult has brown eyes, a purplish cere, a blue-grey bill and pale blue-grey legs. The primary quills are often actually black. From a distance, flying birds can easily appear all black. The immature plumage is sepia-brown above, with a much paler underside than in adults. Immature cinereous vultures have grey down on the head, a pale mauve cere and grey legs. Its massive bill is one of the largest of any living accipitrid, a feature enhanced by the relatively small skull of the species. The exposed culmen measures .Cinereous Vulture (Aegypius monachus) . indianbiodiversity.org Only their cousin, the lappet-faced vulture, with a bill length of up to about , can rival or outsize the bill of the cinereous. The wings, with serrated leading edges, are held straight or slightly arched in flight and are broad, sometimes referred to as "barn door wings". Its flight is slow and buoyant, with deep, heavy flaps when necessary. The combination of huge size and dark colour renders it relatively distinct, especially against smaller raptors such as eagles or buzzards. The most similar-shaped species, the lappet-faced vulture (with which there might be limited range overlap in the southern Middle East), is distinguished by its bare, pinkish head and contrasting plumage. On the lappet-face, the thighs and belly are whitish in adult birds against black to brownish over the remainder of the plumage. All potential Gyps vultures are distinguished by having paler, often streaky plumage, with bulging wing primaries giving them a less evenly broad-winged form. Cinereous vultures are generally very silent, with a few querulous mewing, roaring or guttural cries solely between adults and their offspring at the nest site.
Distribution and habitat
The cinereous vulture is a Eurasian species. The western limits of its range are in Spain and inland Portugal, with a reintroduced population in southern France. They are found discontinuously to Greece, Turkey and throughout the central Middle East. Their range continues through Afghanistan eastwards to northern India to its eastern limits in central Asia, where they breed in northern Manchuria, Mongolia and Korea. Their range is fragmented especially throughout their European range. It is generally a permanent resident except in those parts of its range where hard winters cause limited altitudinal movement and for juveniles when they reach breeding maturity. In the eastern limits of its range, birds from the northernmost reaches may migrate down to southern Korea and China. A limited migration has also been reported in the Middle East but is not common.
This vulture is a bird of hilly, mountainous areas, especially favouring dry semi-open habitats such as meadows at high altitudes over much of the range. Nesting usually occurs near the tree line in the mountains.Eagles, Hawks and Falcons of the World by Leslie Brown & Dean Amadon. The Wellfleet Press (1986), . They are always associated with undisturbed, remote areas with limited human disturbance. They forage for carcasses over various kinds of terrain, including steppe, other grasslands, open woodlands, along riparian habitats or any kind or gradient of mountainous habitat. In their current European range and through the Caucasus and Middle East, cinereous vultures are found from in elevation, while in their Asian distribution, they are typically found at higher elevations. Two habitat types were found to be preferred by the species in China and Tibet. Some cinereous vultures in these areas live in mountainous forests and shrubland from , while the others preferred arid or semi-arid alpine meadows and grasslands at in elevation. This species can fly at a very high altitude. One cinereous vulture was observed at an elevation of on Mount Everest. It has a specialised haemoglobin alpha subunit of high oxygen affinity which makes it possible to take up oxygen efficiently despite the low partial pressure in the upper troposphere.
Behaviour
The cinereous vulture is a largely solitary bird, being found alone or in pairs much more frequently than most other Old World vultures. At large carcasses or feeding sites, small groups may congregate. Such groups can rarely include up to 12 to 20 vultures, with some older reports of up to 30 or 40.
Breeding
In Europe, Eurasian black vultures return to the nesting ground in January or February. In Spain and Algeria, they start nesting in February or March, in Crimea in early March, in northwestern India in February or April, in northeastern India in January, and in Turkestan in January. They breed in loose colonies, with nests rarely being found in the same tree or rock formation, unlike other Old World vultures which often nest in tight-knit colonies. In Spain, nests have been found from to apart from each other. The cinereous vulture breeds in high mountains and large forests, nesting in trees or occasionally on cliff ledges. The breeding season lasts from February until September or October. The most common display consists of synchronous flight movements by pairs. However, flight play between pairs and juveniles is not unusual, with the large birds interlocking talons and spiraling down through the sky. The birds use sticks and twigs as building materials, and males and females cooperate in all matters of rearing the young.Cinereous Vulture Fact Sheet . Lincoln Park Zoo The huge nest is across and deep. The nest increases in size as a pair uses it repeatedly over the years and often comes to be decorated with dung and animal skins. The nests can range up to high in a large tree such as an oak, juniper, wild pear, almond or pine trees. Most nesting trees are found along cliffs. In a few cases, cinereous vultures have been recorded as nesting directly on cliffs. One cliff nest completely filled a ledge that was wide and in depth. The egg clutch typically contains only a single egg, though two may be laid in rare cases. The eggs have a white or pale buff base colour are often overlaid with red, purplish or red-brown marks, being almost as spotted as the egg of a falcon. Eggs measure from in height and in width, with an average of . The incubation period ranges from 50 to 62 days, averaging 50–56 days, and hatching occurs in April or May in Europe.